In recent years, as an electrical storage device to be used for such an application which requires a high energy density and high power characteristics, attention has been paid to an electrical storage device called a hybrid capacitor, in which the storage principles of a lithium ion secondary battery and an electric double layer capacitor are combined with each other. As one example, an organic electrolyte capacitor has been proposed in which a carbon material capable of absorbing and desorbing lithium ions is preliminarily absorbed and supported (hereinafter, sometimes referred to as doped) with lithium ions by an electrochemical method to lower the negative electrode potential, thereby greatly increasing an energy density (for example, see Patent Document 1).
Such an organic electrolyte capacitor is expected to have high performance, but has drawbacks such that when the negative electrode is preliminarily doped with lithium ions, the doping requires a very long time, and it is difficult to uniformly dope the entire negative electrode with lithium ions. Particularly, in a large-size, large capacity cell such as a column shape capacitor having electrodes wound or a square capacitor having a plurality of electrodes laminated, it is difficult to be put into practical use.
To solve such problems, an organic electrolyte battery has been proposed in which each of a positive electrode current collector and a negative electrode current collector has through holes penetrating from the front surface to the back surface, a negative electrode active material is capable of reversibly doping lithium ions, and the negative electrode is doped with lithium ions by electrochemical contact with a lithium metal disposed to face the negative electrode or the positive electrode (for example, see Patent Document 2).
In the organic electrolyte battery in which the electrode current collector has through holes penetrating from the front surface to the back surface, lithium ions can move from the front surface to the back surface of the electrode without being blocked by the electrode current collector. Thus, even in an electrical storage device having a cell structure with a number of electrodes laminated, it is possible to dope, via the through holes, not only a negative electrode disposed in the vicinity of the lithium metal but also a negative electrode disposed distant from the lithium metal with lithium ions by an electrochemical method.    Patent Document 1: JP-A-8-107048 (page 2, second column, lines 38 to 47)    Patent Document 2: International Publication WO 98/033227 (page 11, line 4 to page 12, line 27)
In the above-mentioned capacitor or battery, as a lithium ion supply source for absorbing or supporting (doping) of lithium ions to the negative electrode, a lithium metal foil is mainly used. It is known to use the lithium metal foil with pressure bonding the lithium metal foil to a porous current collector; however, in the related art, upon assembly of the capacitor or the battery, the lithium metal foil is cut into a predetermined size by a metal cutting blade, each cut foil is pressure-bonded to the current collector, and the pressure-bonded cut foils are disposed on an electrode laminate unit in which an electrode layer (positive and negative electrodes) is laminated or wound, thereby assembling the capacitor or the battery.
However, when the lithium metal foil is cut by the metal cutting blade, the lithium metal adheres to the cutting blade, complicating the cutting operation and thus making it difficult to cut in a precise and smooth manner. For this reason, in the past, it has been deliberated to apply an electrolytic solution to the cutting blade or using the cutting blade of a resin material. However, even such deliberation could not avoid lowering of the productivity and is not industrially satisfactory.
In addition, since the lithium metal foil is likely to deform when formed into a thin metal foil having a thickness of about 10 to about 500 μm, for example, it provides poor handling properties upon assembly of the capacitor or battery during or after cutting, thereby deteriorating workability and causing misalignment of the electrodes, which eventually cause deterioration in the quality.